Pallet truck



April 1946- H. J. FRAMHEIN' PALLET TRUCK Filed Feb. 25, 1942 sSheets-Sheet 1 ATTORNEY A9111 1946- H. J. FRAMHEIN 2,399,596

PALLET TRUCK Filed Feb. 25, 1942 3 Sheets-Sheet 2 g z INVENTORQ TFig/91464 ATTORNEY April 30, 1946. H. J. FRAMHEIN PALLET TRUCK FiledFeb. 25, 1942 3 Sheets-Sheet 3 ATTORNEY Patented Apr. 3t), 1946 PALLETTRUCK Herbert J. Framhein, Chicago, Ill., assignor to 'Ifhe Yale & TowneManufacturing Company, Stamford, Conm, a corporation of ConnecticutApplication February25, 1942, Serial No. 432,177

5 Claims.

This invention relates to a lift truck of the type having an elevatingplatform that is adapted to .be lifted relatively to a lifting head.More particularly, my invention relates to a lift truck of the type inwhich the elevating platform is supported by, wheels at its rear end,and is adapted to be lifted at its forward end through lifting meansextending between the lifting head and the elevating platform, thelifting movement of the platform at its forward end, being adaptedthrough suitable means, to move the wheels at the rear end of theplatform to elevate the rear end.

Trucks of the general description given are quite well known in the art,and one type is disclosed in the Hastings Patent No. 2,234,925 and inthe Quayle Patent 2,274,164. In the Hastings ing head, linkage mechanismconnected to the rear wheels of the platform is adapted to move thoserear wheels to elevate the rear end of the platform simultaneously withthe forward end.

The art also includes trucks in which a steering head carries avertically movable steering wheel that may be'moved verticallyrelatively to the truck platform to lift the forward end of thatplatform. In this type of truck, illustrated in the Hennessey Patent No.1,359,372, the rear wheelsupporting links are actuated by the movementof the steering wheel to lift the rear end of the elevating platformsimultaneously withthe lifting of theforward end of the platform. Thistype of truck does not utilize a lifting head and an elevating platformas outlined by Hastings and Quayle. I 1

The truck of my invention utilizes a platform, which unlike that of theHastings and Quayle patents, is mounted for vertical sliding movementrelatively to a lifting head, the mounting means whereby the platform ismounted, on the lifting head being utilized for maintaining the liftinghead and the platform assembled to form a complete truck. Moreparticularly, the mounting means whereby the platform moves verticallyrelatively to the lifting head, comprise rollers which are preferablymounted on the lifting platform and ride in the channels of uprightsmounted on the lifting head. My truck varies from trucks such as the oneshown in the Hennessey patent in that I utilize a lifting head as wellas an elevating platform. I

The vertical movement of the forward end of the elevating platform isemployed to actuate means which are connected to the rear wheels of theelevating platform for moving those wheels relatively to the platform,as will be readily undertstood by those skilled in the art. The meanswhereby the rear wheels are actuated form a novel part of my invention,and comprise an operating member, preferably in the form of a cam, whichis preferably pivotally mounted on the lifting head. .This cam isadapted for movement on its mounting by means carried. on the elevatingplatform, and the preferred form of my invention utilizes as the saidmeans a roller mounted for. movement with ,the elevating platform. n

As a further feature of my invention, I utilize a roller and channelconnection between the elevating platform and the lifting head for notonly maintaining the platform and head assembled, but for limiting thedownward movement of the platform relatively to the lifting head. Asstill a further feature of this portion of my invention, the rollers areadapted to limit vertical movement of the platform by cooperating withfixed portions of the standards in which are formed the channels inwhich the rollers move.

A further feature of importance in my invention, is the particular meansutilized for connecting the actuating cams with the links on which therear wheels of the platform are mounted.

The particular means utilized are preferably in the form of adjustablerods, so that accurate adjustment may be had to place the rear links inproper operating relation to the platform while the cams are in properoperating relation to the lifting head and the means on the platformutilized for actuating the cams. It will of course be appreciated bythose skilled in the art that while I utilize what I describe as cams,and preferably pivoted cams, other suitably mounted mechanism may beadapted for the purpose.

As a further feature of my invention I utilize rear wheels mounted onlinks which are adapted for adjustable movement relatively to theelevating latform, so as to facilitate the proper adjustment of therelationship between the wheel carrying links and the platform on theone hand, and the actuating cams on the other hand. Those skilled in theart will readily appreciate the value of this type of mechanism.

I have thus described my invention generally in order that the basiccontribution of my invention may be better understood. Certainadditional features to be described in the specification, form importantparts of my invention and will be claimed broadly hereinafter. Sincethose skilled in the art will readily understand how my invention may beembodied in forms other than that which I shall herein describe, Ibelieve it important that my patent claims shall be sumciently'broad toprevent the utilization of my contribution to the art in forms otherthan herein presented.

Referring now to the drawings, Fig. 1 is an elevation illustrating myinvention applied to a motorized lift truck of the type described in myapplication, Serial No. 390,931 filed April 29, 194.1, now Patent No.2,327,583, dated August 24, 1943. Fig. 2 is a view looking downwardly onthe truck of Fig. 1 illustrating my invention. Fig. 3 is a verticalsection on the line 3 -3 of Fig. 2 showing the means whereby the liftingmovement of the elevating platform is utilized for imparting liftingmovement to the rear wheels of the elevating platform. Fig. 4 is asection taken along line 4-4 of Fig. 3. Fig. 5 is a perspective view ofthe lifting platform standard adapted for cooperation with the standardof the lifting head. Fig. 6 is a perspective view of a portion of thelifting head showing the standard comprising a pair of uprights. Fig. 7is a perspective exploded view of means utilized for adjusting theconnection between the rear wheel supporting links of the platform andthe operating mechanism for moving those links. Fig. 8 is a view of amodified form of means which may be utilized for the particular purpose.1

Fig. 9 is a view similar to Fig. 1 but illustrating a somewhat differenttype of connection between the rear wheel supporting links and theactuating mechanism therefor, as well as a novel means for adjusting theposition of the wheel supporting links. Fig. 10 is a view taken lookingdownwardly on the platform of Fig. 9.

Referring now more particularly to the drawings, the lifting head of mytruck is designated generally by the reference numeral i9 and is of thesame general type shown in my earlier application, Serial No. 390,931,filed April 29, 1941, now Patent No. 2,327,583, dated August 24, 1943.The lifting head i carries a battery support II in which is mounted abattery l2 which provides power for the propelling motor of the truckused to drive the wheel I (la that supports the lifting head It. Theconstruction of the forward end of the lifting head I0 is of noparticular importance to this application and no further descriptionthereof will be given.

As is best seen from Figs. and 6, the rear end of the lifting head II)has welded thereto a pair of gusset plates l3, and welded in turn to theplates l3 are the uprights l4, channeled at I5 to provide ways for therollers I6. The rollers l6 are suitably mounted on pivot shafts llrelatively to the plate portions I 8 of the elevating platform standardI9. The mounting means for the rollers I6 are not shown in detail nordescribed in detail, they being constructed and mounted as is common inthe lift truck art, and as is shown in numerous patents. The cooperationbetween the rollers l6 and the channels ii of the uprights |4, is suchthat the elevating platform standard l9 will move vertically relativelyto the uprights l4, and will be incapable of any pivotal movementrelatively to those uprights, and therefore relatively to the liftinghead I0. Therefore it may be said that the coaction between the rollersl8 and the uprights l4 forms an assembled truck having an elevatingplatform and a lifting head, and with the platform adapted for verticalmovement on the lifting head and I held against pivotal movementrelatively to said lifting head.

The lower ends of the channels it: of uprights I4 are closed by crossbars 20, and in the lowermost position of the elevating platformillustrated in Figs. 1, 3 and 4, the bottom rollers its will rest on theupper surfaces of the cross bars 29, thus limiting the downward movementof the elevating platform standard l9 relatively to the lifting head.

As may best be seen in Figs. 3, 4 and 5, the upper portion of thestandard I9 carries a pair of lugs 25 which are bored at 25 for thepassage of a short shaft 21. The shaft 2 is adapted to secure to thelugs 25 the upper end 28 of a ram 29 forming part of a hydraulic liftingassembly 39. The lower end of the hydraulic lifting assembly 35 ispivoted through a pin it relatively to a pair of lugs 82 and 33 suitablysecured to the lifting head 49, as by welding. The lugs'2i2 and as aresuitably drilled at 34 and 35 for the passage of the pin 3!, the pinbeing itself retained against movement by a bolt 38 best illustrated inFig. 4, and shown also in Fig. 3. Through the use of suitable pumpingmechanism carried on the lifting head, and actuated by the treadle 39a,the ram 29 will be moved to impart lifting movement to the standard l9,with the standard l9 being suitably guided by the rollers l8 ridingwithin the channels 15 as has already been set forth.

Those skilled in the art will readily appreciate that by reversing theuprights i4 so that the channels l5 will extend inwardly rather thanoutwardly, the width of the truck may readily be changed. They willfurther appreciate that by merely welding additional gussets, such asthe gussets l3, relatively to the lifting head, the width of thetruckmay be further increased.

In the truck illustrated in Figs. 1 to 5, the elevating platform is ofthe U-shape type adapted for cooperation with a pallet. Each of the U-shape portions 39 is welded as at 38 to the standard I 9 and extendsrearwardly as is clearly shown in Fig. 2. Since the U-shaped portions 39are identical, I shall describe the construction of but one of the saidportions. Referring t6 Figs. 1 and 2, it will be noted than an anglemember 40 is welded in transverse reinforcing relation to the U portion39 for stiffening its construction, and for cooperation with surfaces 4|of a rear wheel supporting link 42. This rear wheel supporting link 42is pivoted on the shaft 43 relatively to the U portion 39, and in thelowered position of the platform illustrated in Fig. 1, has its uppersurfaces 4l lying against the angle member 40 to determine the lowermostposition of the rear end of the platform of the truck. For rotating thelink 42 to lift the rear end of the U portion 39 of the elevatingplatform, the link 42 is hinged at pin 44 to a flat tension rod 45 whoseend portion 46 fits about the pin 44 in the manner of a hinge plate. Thetension rod 45 extends forwardly toward the lifting head and thestandard it of the elevating platform and is actuated as will bedescribed shortly.

Referring now more particularly to Figs. 3, 4 and 5, it will be notedthat at each side of the standard 19, and equally spaced from itscenter, is an arm 50, on the end of which is mounted a roller 5| whichmay be similar to the rollers l6, although preferably considerablysmaller. Mounted on each of the gusset plates I 3, which support theuprights I4, is what I choose to term mechanism an actuating cam 53. Thecams 53 are preferably pivotally mounted relatively to the gusset platesI 3 through stub shafts 54, and are held on the shafts 54 for pivotalmovement through suitable washers 55 and nuts 58, all as will be quiteapparent to those skilled in the art. Each of the operating cams 53 ispivotally connected through a pin 51 to a flat tension rod 58, theconnection being the same as that between the rods 45 and the pins 44 ofthe rear wheel links 42.

The rods 45 and 58 are suitably connected by adjustable means to bedescribed presently so that tension applied to the rods will rotate thelinks 42 about their shafts 43 to lift the rear ends of the pair ofU-portions 39 comprising the elevating platform of my truck. Thismovement is applied to the rods by rotation of the operating cams 53 bythe rollers 5| as the standard [3 of the elevating platform movevertically through action of the ram 29 of the hydraulic lifting 30. Thelowered position of the standard I 9 is well illustrated in solid linesin Fig. 3, and the positions of the operating cams 53 and rollers 5|when the lifting platform is in itslowest position are there also shownin solid lines. The dash and dotted line position in Fig. 3 of a roller5| and one of the actuating earns 53, illustrates the positions of theparticular parts when the standard I! has been elevated. It is obviousthat when the operating cams 53 are rotated clockwise by rollers 5|,they apply tension to the rods 58 and 45 to rotate the links 42. Forlimiting the movement of the operating cams 53, I use pins 60, whichtake the form of studs threaded into the gusset l3, as well illustratedin Figs. 3 and 4.

For economy in manufacture it is best to utilize the two rods 58 and 45rather than a single rod. 1 have also found it best to utilize the tworods 58 and 45 for connecting each of the operating cams 53 with itsparticular wheel supporting link 42, in order that the operatingrelationship of Fig. 1 may readily be obtained without extremelyaccurate manufacture of the several parts. At this point, particularattention i called to the fact that the actuating cams 53 are mounted onthe lifting head and are connected to the links 42 that are mounted onthe elevating platform. This arrangement is most novel, and allows forthe use of actuating cams that do not protrude below the elevatingplatform. One form of means for utilizing the two rods 45 and 58 isshown in Fig. '7 where the rods 45 and 58 are anchored at their endsrelatively to bars 65 as by welding at 56, inserts 51 being utilized toprovide a smooth finished surface to the bars.

Each of the bars 65 is bored as at 58 for the Passage of bolts 69..Springs III are placed about the bolts 59 and lie between the bars 65when the bolts are secured relatively to the bars 55 by the nuts ll asis well illustrated in Fig. '7. It is obvious that by rotating the nutsH on the bolts 59, the effective length of the rods 58 and 45 may beaccurately determined, the distance between the bars 65 being well takenup by the springs 10.

In Fig. 8 I show a modified form of the invention of Fig. 7, in which Iutilize bars 45a and 58a, and connect the said bars by a turnbuckleassembly designated generally by reference numeral 12. It is quiteobvious that through the use of the turnbuckle arrangement 12, theeffective len th of the two bars 58a and 454: may be readily determined.

Referring now more particularly to Figs. 9 and 10, I illustrate a formof my invention in which I use a form of rear wheel supporting linkwhich is is diflerent from that illustrated in Figs. l-to 8 inclusive.In the modification of Figs. 9 and 10 I use also a different type ofconnection between the rear wheel supporting links and the actuatingcams 53 through which those links are actuated. Incidentally, in theform of my invention shown in Figs. 9 and 10, I show a slightlydifferent form of actuating cam designated by reference numeral 53a. Theremaining parts are the same as those illustrated in the firstmodification, and therefore bear the same reference numerals.

Referring now to Figs. 9 and 10, .each of the rear wheel supportinglinks is designated by reference numeral 15 and is pivoted on shaft 16relatively to a bearing block 11 whose u er surface bears against theunder surface 19 of the inverted channel member that forms one of the Uportions sea of the platform of the truck. Where an inverted channel isnot utilized, it is obvious that other means will be provided so thatthe block Tl will slide relatively to the under surface of the platform,all as will be clearly understood by those skilled in the art.

Link 15 has a surface 8!, which in the lowered position of the platformillustrated in Fig. 9, bears against the under surface 19 of theinverted channel 80 for limiting the downward movement of the rear endof the elevating platform, all as I have described with reference to myearlier modification. The block H is secured to a pair of bolts 82 whichextend through parallel bores in a block 33 welded to the underside ofthe channel 85. a It is obvious that by adjusting the positions of thebolts 82 relatively to the fixed block 83 and securing the bolts in saidpositions by nuts 82a, the bearing block 18 will be adjustedlongitudinally of the elevating platform or inverted channel 88. In thisway, a ready adjustment of the position of the rear wheel supportinglink 15 is obtained. This position may be adjusted so that the severaloperating parts will be in a predetermined position when the platform isin its lowered position of Fig. 9, all as will be clearly understood bythose skilled in the art.

A tension rod 85, which may be similar in form to the rods 45 and 58 ofmy first modification, is pivoted at 86 to the operating cam 5311 asshown in Fig. 9, and through the pin 81 to the link 15, whereby themovement of the operating cam 53a by the roller 5la of the elevatingplatform, will rotate the link 15 to elevate the rear end of theplatform as ha already been indicated.

In pallet trucks, it is desirable that rollers be utilized for assistingthe truck in entering between the fioors of the pallet. In my truck ofFigs. 9 and 10 I show such rollers at the rear end of the platformdesignated by reference numbers 88 and 89. I utilize an additionalroller 90 mounted on the pin 81, and a fourth roller 91 mounted on thebearing block TI. The roller 90 ha the additional function of protectingthe pivoted connection between the rod and the link 15 as is I movementrelatively to said lifting head whereby to form with said lifting head acomplete truck, means extending between the forward end of said platformand said lifting head for lifting the forward end of said platformrelatively to said lifting head, a cam member pivotally mounted on saidlifting head, a rod connecting said cam member with said wheelsupporting means at the rear of said platform, a roller mounted on saidplatform and bearing against said cam member as the front end of saidplatform is lifted, whereby to rotate said cam member and through saidrod actuate said wheel supporting means to lift the rear end of saidplatform, and a stop on said lifting platform against which said cam ismoved by said roller.

2. In a truck of the class described, an elevating platform, a wheelsupporting link pivoted to the rear end of said platform, actuatingmeans for moving said wheel supporting link, a connecting rod forconnecting said link to said actuating means pivoted at one endto saidlink and terminating at its other end short of the end of said actuatingmeans, an adjustable connector connecting the end of said rod and theend of said actuating means and bridging the gap therebetween, and aspring pressing said ends away from one another to maintain said gap.

3. In a truck of the class described, an elevating platform, a wheelsupporting link pivoted to the rear end of said platform, actuatingmeans for moving said wheel supporting link, a, connecting rod forconnecting said link to said actuating means pivoted at one end to saidlink and termi nating at its other end short of said actuating means, anadjustable bolt connecting said rod and said actuating means andbridging the gap therebetween, and a spring between said actuating meansand said rod for yieldingly resisting movement of said rod toward saidactuating means.

4. In a truck of the class described, an elevating platform, a wheelsupporting link, a bearing on which said wheel supporting link ispivoted, the upper surface of said bearing lying against the undersurface of the said platform for sliding movement on said under surface,and screw threaded means for adjusting the position of said bearingrelatively to said surface.

5. In a truck of the class described, an elevating platform, a wheelsupporting link, a bearing on which said wheel supporting link ispivoted, the upper surface of said bearing lying against the undersurface of the said platform for sliding movement on said under surface,and means movable relatively to means fixed to said platform foradjusting the position of said bearing relatively to said surface.

HERBERT J. FRAMHEIN.

